Multiple Morphological Measurements as Larval Indicators for <I>Saperda vestita</I> (Coleoptera: Cerambycidae)

Abstract

Ten sclerotized morphological structures were measured to determine the number of instars of the linden borer, Saperda vestita Say (Coleoptera: Cerambycidae). Linear regression analysis revealed a significant relationship between maximal cranial width and the other structures measured, including length of the terminal labial palpomere, length of the first thoracic spiracle, width of the first thoracic spiracle, length of clypeolabral suture, length of frontoclypeal suture, cranial width measured at antennal insertions (from outside edges), maximal prothoracic width, mesal pronotal length, and length from apical margin of labrum to distal end of the prothorax. Linden borer instar number was determined through the use of frequency distribution diagrams. Mean, standard error of the mean, Dyar’s ratio, and Crosby’s ratio were calculated and evaluated for each instar designation to confirm that none of the five to six instars of S. vestita was overlooked.